How To Calculate Unit Price: Steps and Calculator

Unit price = Total price / Total quantity. This calculation shows what a customer pays per ounce, pound, liter, or individual item, making different package sizes easier to compare.

In CivicScience research published in April 2025, 56% of Americans surveyed said they’d noticed grocery packaging getting smaller without a matching price drop. Comparing unit prices helps shoppers spot shrinkflation, a type of price increase.

Learn how to calculate unit price, compare it with your business’s cost per unit, and use both figures when pricing products.

What is unit price?

Unit price is the selling price for a standard quantity of a product, such as one pound, one fluid ounce, one kilogram, or one individual item. It lets customers compare prices across packages containing different quantities of the same or similar products.

For example, a 32-fluid-ounce carton of juice might cost $4, while a 64-fluid-ounce carton costs $6.40:

• 32-fluid-ounce carton: $4 / 32 = 12.5¢ per fluid ounce.
• 64-fluid-ounce carton: $6.40 / 64 = 10¢ per fluid ounce.

The larger carton costs 20% less per fluid ounce. When comparing shelf labels, check that both prices use the same measurement. Convert prices to a common unit first.

US unit-pricing rules vary by jurisdiction. The National Institute of Standards and Technology guide to retail pricing laws identifies mandatory provisions in states such as Connecticut and New York, plus voluntary provisions elsewhere. Check with the weights and measures agency in each state where you do business to learn which rules apply.

You can display unit prices on Shopify through your product settings:

1. Open Products in your Shopify admin and select a product or variant.
2. In Pricing, click Unit price. Enter the product’s Total amount and choose a Base measure, such as 100 grams or 1 liter.
3. Click Done, then Save.

Shopify uses these measurements and the product’s selling price to calculate the unit price. Online Store 2.0 themes display it automatically on product, collection, cart, and checkout pages.

Vintage themes may need code changes. The unit price updates when you change the product’s price.

Unit price vs. cost per unit

Unit price tells customers what they pay for a given quantity. Cost per unit, also called unit cost, tells a business what it spends to produce or acquire each item.

For manufacturers, product cost includes fixed expenses, such as factory rent, and variable expenses, such as raw materials. Higher production volumes spread fixed costs across more units.

To calculate a profit margin, compare price and cost for the same quantity. If the 64-fluid-ounce carton sells for $6.40 and costs the retailer $4 to acquire, it generates $2.40 in gross profit:

Gross profit margin = ($6.40 − $4) / $6.40 x 100 = 37.5%

The same carton has a 60% markup: $2.40 / $4 x 100. The difference between markup and margin calculations is the denominator: markup uses product cost, while margin uses selling price.

That gross profit must also cover operating expenses and taxes. A higher unit cost reduces the margin if the selling price stays the same. A break-even analysis estimates how many units you need to sell at a given price to cover your fixed and variable costs.

How to calculate unit price

Unit price = Total price / Total quantity

Use this retail math formula to calculate the price per ounce, liter, or individual item.

Follow these four steps to compare prices across different package sizes:

1. Find the item’s total price.
2. Identify the total quantity and unit of measure.
3. Use the same unit.
4. Divide the total price by the number of units.

1. Find the item’s total price

Use the package’s current selling price after any retail markdowns. Subtract any additional discount you qualify for. For a multibuy offer, use the total price and quantity of all packages included in the deal.

2. Identify the total quantity and unit of measure

Check the package label for the product’s net weight, volume, or item count. Use the quantity of the contents, excluding the packaging.

For multipacks, calculate the total quantity. A pack containing six 12-fluid-ounce cans holds 72 fluid ounces.

3. Use the same unit

Both prices must use the same unit for a valid comparison. Comparing a price per pound directly with a price per ounce gives a misleading result.

Convert the package quantities to a common unit before calculating:

• Weight. A 2-pound bag contains 32 ounces because each pound equals 16 ounces. You can now compare it with a bag labeled in ounces.
• Volume. A 1.5-liter bottle contains 1,500 milliliters. You can now compare it with a bottle labeled in milliliters.

Keep weight and volume separate: ounces describe weight, while fluid ounces describe volume.

4. Divide the total price by the number of units

Divide each package’s price by its quantity in the chosen unit. For paper towels, assume both packages have the same sheet size and number of sheets per roll:

Package B costs about 11¢ less per roll. If the rolls contain different amounts of paper, compare prices per 100 sheets of equal size or per square foot.

Flipping the formula (quantity / price) gives you units per dollar, or how much product $1 buys. Package B provides about 0.64 rolls per dollar: 8 / $12.49. A higher figure means more product for your money.

Unit price calculator

You can calculate and compare unit prices in Excel or Google Sheets. Set up three columns and enter these values and formulas:

Place the headings in row 1 and the product details in rows 2 and 3. The formulas divide each price by its quantity. Format column C as currency and label it with the unit you’re comparing, such as “Price per roll.” Use the same measurement unit for every quantity in column B.

For business pricing decisions, use Shopify’s profit margin calculator to explore how your product costs and markup affect the selling price and profit margin.